docs: def bend(self, bends, frame_rate=None, over_sample=None):
          """TODO Add docstring."""
          self.command.append("bend")
          if frame_rate is not None and isinstance(frame_rate, int):
              self.command.append('-f %s' % frame_rate)
          if over_sample is not None and isinstance(over_sample, int):
              self.command.append('-o %s' % over_sample)
          for bend in bends:
              self.command.append(','.join(bend))
          return self